The following invention relates generally to mounting components on printed wiring boards and more specifically to using die stacks to mount components on printed wiring boards.
Printed wiring boards are often used to establish electrical connections between various electronic devices. Printed wiring boards can be rigid or flexible and include a single functional layer or multiple functional layers. The length of the circuit trace connecting the electrical devices can impact on the operation of the devices. A longer track can introduce additional inductance and can also result in additional interference. Reducing the length of the path that signals must travel between components can decrease inductance and signal interference.
One approach to reducing the length of the signal path between components is to mount components as a Thin Small Outline Package (TSOP) stack. A TSOP stack is created by mounting TSOP components upon each other. TSOP stacking has been used in a variety of products, including high density memory modules, and is typically used with applications having switching speeds that are less than 333 MHz.
Another approach is to use Ball Grid Array stacking or BGA stacking. BGA stacking involves the use of multiple BGA components, which are stacked on top of each other. BGA in applications involving switching speeds that are less than 800 MHz.